'Radio Sweepstakes with Control condition - Environment & Food Choice' (AsPredicted #79021)
Author(s) Maria Langlois (INSEAD) - langlois@smu.edu Pierre Chandon (INSEAD) - pierre.chandon@insead.edu
Pre-registered on 2021/11/04 - 01:26 PM (PT)
1) Have any data been collected for this study already? No, no data have been collected for this study yet.
2) What's the main question being asked or hypothesis being tested in this study? We expect that exposure to different environments for a brief period of time will have a significant impact on the healthiness of their food choices – and specifically, that exposure to nature will lead to healthier food consumption decisions when compared to exposure to urban environments.
3) Describe the key dependent variable(s) specifying how they will be measured. In a hypothetical lunchbox meal choice task, participants will choose a drink, main course, and side dish, which are framed as a free meal offering that they would be able to consume while enjoying the view depicted in one of the 3 scenes (i.e., their randomly assigned condition). Respondents will have the option to choose 1 out of 4 drinks (two of which are healthy & two of which are unhealthy), 1 out of 4 side dishes (two of which are healthy & two of which are unhealthy), and 1 out of 4 main courses (two of which are healthy & two of which are unhealthy).
4) How many and which conditions will participants be assigned to? 3 Conditions: Nature versus Urban versus Control, between-subjects design
Participants will be randomly assigned to one of the three conditions. The conditions will be displayed in the form of a photographic scene exhibiting a window with either a nature view, an urban view, or closed curtains (control).
5) Specify exactly which analyses you will conduct to examine the main question/hypothesis. We plan on conducting analyses which compare food choice behavior across environmental contexts using binomial logistic regressions. Furthermore, we will utilize conditional logit in order to account for the fact that the same individuals are making a 1 in 4 choice decision (e.g., one out of 4 drink options) on 3 occasions (for a drink, a main dish, and a side).
6) Describe exactly how outliers will be defined and handled, and your precise rule(s) for excluding observations. Participants will be excluded: if they indicate that they are not using an eligible device, if meta-data reveals an operating system or desktop resolution that is likely to be a cell phone/tablet (browser resolution height under 500), and if they failed the attention check (which consists of a photo recall question).
7) How many observations will be collected or what will determine sample size? No need to justify decision, but be precise about exactly how the number will be determined. The sample size was determined based on the effect size observed in a field study that utilized nature vs. urban environments as the IV. Using the values from this previous study yielded n=224. In order to account for three times the analyses, given the inclusion of a control condition (so, nature vs. urban, nature vs. control, and urban vs. control), this would yield a sample size of 672. Furthermore, we will need to account for attention check failure and the use of ineligible devices; thus, we will collect 5% more observations. Therefore, we aim to recruit 706 respondents.
8) Anything else you would like to pre-register? (e.g., secondary analyses, variables collected for exploratory purposes, unusual analyses planned?) We capture dieting behavior and sex for exploratory purposes.
